Safety on two major New South Wales highways has been placed under immediate review by the state's Roads Minister.

Duncan Gay has agreed to examine the Princes and Pacific highways.

NRMA president Wendy Machin says about 60 per cent of the Princes Highway has been classified as "risky", based on a study of crash data.

The NRMA commissioned report found a 47 per cent increase in deadly crashes on the highway between 2004 and 2009.

"Anybody that knows the Princes Highway knows that sections of it are very narrow, very windy, with a lot of trees and rock shoulders close to the road," Ms Machin said.

In the state's north the Deputy Premier Andrew Stoner has called for upgrades on the Pacific Highway to be brought forward after another fatal accident near Macksville yesterday.

A man died when his car collided with a b-double truck carrying chemicals early yesterday morning, causing an explosion.

Mr Stoner says the section of highway between Kempsey and Urunga has become known as the "death zone".

"It is single carriageway only, it has a huge volume of heavy trucks, especially at night," Mr Stoner said.

"Basically any sort of situation that you get into on that stretch of road is potentially fatal."

Mr Gay is backing the call from his National Party colleague.

"Yes, that is an appropriate call and I will be working with Andrew," Mr Gay said.

Ms Machin says the Pacific Highway has been significantly upgraded.

"There is a lot of work going on there, but there's an awful lot still to be done. The Princes Highway hasn't really even made it onto the radar of government, and we want to get it there and keep it there," she said.